Power-hammer



UNITED STATES PATENT OFFICE.

JAMES BERNARD SWEENEY AND ROBERT WALLACE LAIRD, OF ST. JOHNSBURY,VERMONT.

Powl-:R-HAMMER.

SPECIFICATION forming part of Letters Patent No. 514,787, dated February13,1894.

Application filed May l, 1893. Serial 110.472,538. (No model.)

' SWEENEY and ROBERT WALLACE LAIRD, both of St. Jo'hnsbury, in thecounty of Caledonia and State of Vermont, have invented a newv andImproved Power-Hammer, of which Athe following is a full, clear, andexact description.

Our invention relates to improvements in power hammers; and the objectof our invention is to produce an extremely simple and inexpensivehammer, which is adapted to deliver an elastic blowsimilar to that givenwith a hand hammer, which is provided with a well balanced tilting belveto actuatethe hammer,

and which has a simple means of adj usting the hammer so as to regulateits stroke.

To these ends our invention consists of certain features of constructionand combinations of parts, as will be hereinafter described and claimed.f

Reference is to be had tothe accompanying drawings forming a part ofthis specification, in which similar figures of reference indicatecorresponding parts in all the views.

Figure 1 is a side elevation of the machine embodying our invention,with a part of the helve broken away. Fig. 2 is a broken front View ofthe machine. Fig. 3 is a sectional plan view of the same; and Fig. 4 isa horizontal section on vthe line 4-4 of Fig. 1.

The machine is provided with a suitable frame 10, which has a thickenedtable 11 at its'front end, in which is dovetailed the anvil 12 which maybe of any suitable construction, and above this anvil is a verticallyreciprocating hammer 13 which is carried bythe head 14, being dovetailedtherein, as shown in Fig. 1, and the head is held-to slide up and downon the front lof the frame andin slideways 15, the head being preferablyprovided with flanges 16 which Lenter the slideways. The head 14 ishollow at its upper end to fa-v cilitate its connection with the tiltinghelve 17 which actuates the hammer head and hammer, this helve beingcarried by a transverse shaft 18 inthe upper part of the machine frame,and at its rear end the helve is provided with a suitable adjustablecounterbalance 19 which enables the helve to be prop erly balanced andeasily moved. The helve 17 is split at its forward end and vthe walls ofthe split portion liare vertically, as shown by dotted lines 2O in Fig.1, and in this split portion of the helve is held a strong dat spring2l, this being fastened in place by a'bolt 22 or equivalent fastening,and the Haring shape of the split end of the helve enables thev springto bend easily over the walls of the split or slot without excessivestrain. The frontend of the spring 21 projectsrinto the head 14 and isheld in a'box 23 which has trunnions 24 pivoted in boxes 25, these beingheld to slide inl horizontal slots 26 in the sides of the head 14, and aconnection is thus formed between the spring and the head, which causesthe spring when sprung, t0 move the head vertically and which permitssufficient freedom of movement to avoid friction.

The shaft 18 is driven bya suitable pulley 1Sa or equivalent drivinggear, and it carries an eccentric 27 which actuates a depending rod 28,see Figs. 1 and 3, and moves the rod up and down. The eccentric rod 28is pivoted at its lower end to atiltinglever 29 which is held in anearly vertical position and is fulcrumed on a stud 30 which isjournaled in boxes 3()a which are adapted to slide in the curved slot 32of the main frame 10, as shown in Fig. 1. The slot 32 describes an arcof a circle, whose center is the shaft 18, so that the boxes 30a4 may bereadily adjusted in it. The stud 30 is screw threaded and provided atits outer end with a wheel nut 31, and as the central portion of thelever 29 bears against the inner box 30a, it will be seen that bytightening the wheel nut, the boxes may be clamped firmly to the frameand the position of the stud 30 fixed. The object of this arrangement isto provide for easily adjusting the hammer to metals of differentthicknesses.

-It will be seen that by loosening the wheel nut 31, the boxes 30a maybe pushed forward in the slot 32, so as to swing forward the rod 28,thus tilting the shaft 18 and helve 17 and raising the hammer head. Theboxes may then be fastened in place as described, and it will be seenthat the position of the hammer head may thus be very nicely adjusted.

The rear end of the lever 29 is pivoted to a pitman 33 which extendsupward, and this IOO connects at its upper end with a bolt 34. whichprojects through a longitudinal slot in the rear end of the helve 17,and the bolt is provided at one end with a wheel nut 36 by which thebolt may be fastened in a desired position, the arrangement being likethat described above for fastening the stud 30; and by this means theupper endof the pitman 33 maybe adjusted and fastened atany point in theslot 35 so as to bring it the right distance from the pivot of the helve17 to give the proper stroke to the helve and the hammer with which thehelve is connected.

It will readily be understood that the adjustment of the stud 30 in thedirection of the anvil, for instance, will necessarily draw downward onthe pitman, which will raise the front end of the helve and with it thehammer, and thus the movement of the hammer will be within higher pointsthan before, to accommodate thicker metal on the anvil.

The machine is operated by setting the shaft 18 in motion and when thisis done, the eccentric 27 moves thepitman 28 up and down, thus tiltingthe lever 29 and actuating the helve 17 by the pitman 33 which connectsthe helve with the lever 29. The swinging movement of the helve causesthe head 14 to be moved up and down and the spring connection betweenthe head and the helve causes the hammer, on its descent, to deliver anelastic blow, as the spring has a freedom of move` ment correspondingvery much to the swinging of a persons arm.

Having thus described our invention, We claim as new and desire tosecure by Letters Patent- 1. A power hammer, comprising a tilting helvehaving a split end, a reciprocating hammer arranged opposite the splitend of the helve, a spring held in the split end of the helve andprojecting into the hammer head, and a box to receive the spring, thebox being pivoted in the hammer head and held to slide horizontallytherein, substantially as described.

2. A power hammer, comprising a vertically reciprocating hammer, atilting helve having one end elastically connected with the hammer todrive the same, a revoluble driving shaft forming the fulcrnm of thehelve, a tilting lever arranged parallel with the helve and having anadjustable fulcrum, mechanism for tilting the lever by the movement ofthe driving shaft, and an adjustable connection between one end of thelever and the helve, substantially as described.

3. A power hammer, comprisinga supporting frame having a revolubledriving shaft in its upper portion, an anvil carried at the frontend ofthe frame, a helve pivoted on the driving shaft, a verticallyreciprocating hammer head, a flexible connection between the hammer headand helve whereby the tilting of the helve will move the hammer head, atilting lever pivoted in a horizontally adjustable bearing beneath thehelve, an eccentric and rod connection between the driving shaft and oneend of the tilting lever, and a pitman connecting the opposite end ofthe lever to the helve and adjustable longitudinally on the latter,substantially as described.

4. A power hammer having its helve fulcrnmed intermediate of its length,a power shaft, an eccentric on the shaft, a rocking arm havingconnection at one end with said eccentric, a pitman connected with theopposite end of the rocking arm, and with the helve at a point on thelatter beyond its fulcrum, and an adjustable fulcruin for said rockingarm, substantially as described.

JAMES BERNARD SWEENEY. ROBERT WALLACE LAIRD. Witnesses:

O. A. GROW, A. B. PRINGLE, JOHN R. WHITNEY.

